Heat derivative of china wood oil



A ril 23, 1935. w. NANFELDT 1,998,768

HEAT DERIVATIVE OF CHINA WOOD OIL Filed Oct. 5, 1952 44 ii: 9 i3 2-; i

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7 INVENTOR 19 f I V/LL/AH NmvFz-zar zgmp '6 BY ATTORNEY Patented Apr. 23, 1935 UNITED STATES PATENT OFFICE HEAT DERIVATIVE OF CHINA WOOD OIL Application October 3,

9 Claims.

This invention relates generally to vegetable oils and specifically to that type of vegetable oil commonly referred to as china wood oil, china nut oil, china oil, wood oil, tung oil, eleococca, and

various other terminology more or less limited in use. In this specification I will refer to the oil as china wood oil.

The use of china wood oil has become widespread in the manufacture of varnishes, waterproof coatings, oil cloths and fabrics, and many other products, because of the peculiar and valuable properties it possesses including that of waterproofing and of exceptional quick drying, comparing favorably in this respect with linseed oil. There have been, however, several difliculties involved in the treatment of the raw oil which has lessened its value and limited its scope of use. Among these difliculties may be mentioned the outstanding characteristic of gelatinization with heat and its inability to withstand high temperatures, unless combined with other substances.

The objects of the invention are, among others, to provide apparatus for heat treating china wood oil which obviates danger of fire; to provide apparatus for treating china wood oil which is enentirely enclosed; and to provide apparatus for heat treating china wood oil which will permit automatic procedure in the carrying out of the treatment.

It is a further object of the invention to provide a process for treating china wood oil which will produce separated fractions of the raw product,

one of light density and the other of relatively heavy density; to provide a process wherein danger of polymerization due to heat-treatment is obviated; and to provide a process which elimihates the necessity for careful treatment of the product during the heating operation.

It is a further object of the invention to provide a product obtained as a derivative of china wood oil which has a density of approximately 0.86 taken at 32 C. and referred to water at 20 C., which acts as a solvent for cellulose, which acts as a plasticizer or solvent for rubber, which acts as a solvent for polymerized china wood oil, which is miscible with water forming an emulsion therewith, which has high penetrating power in woods and fabrics, which acts as an efiicient solvent for paints, and which is a solvent for natural resins.

Still another object of the invention is to provide a product derived from china wood oil, which has a specific gravity approximately the same as water, which acts as a plasticizer for rubber, which is miscible with water, which readily penetrates woods and fabrics, which withstands a temperature in excess of 850 F., which shows no tendency to polymerization when subjected to heat, which is readily miscible with other vege- 1932, Serial No. 635,998

table, animal and mineral oils for lubrication and other purposes, and which may be fluxed with resin.

In the accompanying drawing I have shown an elevation, partly in section, of apparatus which may be used in my process of treating china wood oil.

In the drawing the numeral l0 indicates the heating unit and the numeral ll the condensing or reflux unit. The heating unit includes a stove or furnace l2 of tubular construction, in which is mounted a tubular kettle 13, the base M of which terminates above the base l5 of the stove to permit insertion of the heating element l6. heating element may take the form of an oil heater having a fire plate I1 and an'oil conduit l8 connected to a source of supply. The kettle I3 is formed of a cylinder 9 and a conical member 30 which is secured to the cylinder by engagement of outwardly turned flanges 3| and which terminates at its upper end in the constricted outlet pipe 32. The capacity of the kettle is such that when the crude china wood oil 19 is heated, there is ample room for expansion of the fluid.

I have indicated at 20 the inlet in the top of the kettle and the outlet 2! at the base of the kettle, the inlet consisting of a plug and the outlet a conduit with a valve 22. I have also provided for measuring the temperature of the oil content of the kettle, a thermostat element 23 provided with a connection 24 to the indicator 25 which is mounted upon a support 26 attached to the kettle wall. As is apparent from the drawing, the heat from the heating element passes up the sides of the kettle 24 in the space 21 between the walls of the kettle and the stove. Fresh air enters in the stove at its base in the apertures 28, and the burned gases escape through the aperture 29. I have provided means for aiding in preventing fire due to accidental leakage of fluid at the kettle junction 3! in an annular member 8' positioned around the kettle cylinder 9 above the top 1 of the furnace casing and below the flange junction 3!. The member 8 has an upwardly and outwardly flaring base, thus forming a receptacle for fluid leaking from the joint 3i and preventing contact of the fluid with the hot surface of the stove I2.

Enclosing the open end of the pipe 32 is a trap 33 of box formation, which in its base receives the end of the pipe 32, the pipe extending within the interior of the trap so that its end is spaced from the base of the trap. This permits the accumulation of liquid within the trap from its base to the level of the mouth of the tube 32.

At the top of the trap 33 connection is made by means of the pipe line 34 to the reflux or condensing unit II. This reflux unit in the main consists of a coil of pipe 35 wound about a cylin- Theder 38 so that the turns of the coil lie within a drum having a hollow center 31 formed by the cylinder 36 and an outer cylindrical drum surface 38, the cylinders 36 and 38, by means of the end plates 38 and 40, forming a closed hollow interior adapted to receive cooling water or other fluid. Arrinlet pipe connection 4|, controlled by the valve 42, is placed adjacent the top of the drum and a pipe connection 43 and valve 44 are placed adjacent the base thereof.

The reflux coil 35, as before stated, is within the hollow drum and is subject to the cooling fluid therein so that heated gases within the coils are cooled and condensed, and the resulting liquid passes by gravity into the trap 33. The upper end of the coil extends through the upper wall of the condenser II in a vertical open-ended. stand pipe 45. A branch pipe 46 is brought off the stand pipe 45 and through the open hollow interior 31 of the condenser ll into a receptacle 48 provided with an outlet pipe 8 and valve 5. Connection is also made from the receptacle 48 to the base of the trap 33 by means of the pipe 48, there being a valve in the pipe 48 to prevent flow of liquid from the trap exoept at will. The pipe 46 provides a gas outlet when liquid flows into the receptacle 48 through the pipe 48.

In the operation of the apparatus as above described and as illustrated in the drawing, the raw commercial china wood oil is first placed in the kettle 13 in an amount equal approximately to one-fourth of the capacity of the kettle. This amount isv required because during the heating operation there is a very considerable expansion of the liquid at which it seems to undergo certain chemical and physical changes, and the capacity of the kettle must be sumcient to prevent overflow, particularly as the oil is inflammable. Heat is then applied by means of the oil burner in such quantities, that the oil is brought up to a temperature of 680 F. at a rate equal to or in excess of 33 F. per minute. This rate of heat has been found necessary for the reason that if a lower rate is used, such as 30 F. per minute, for example, the china wood oil would gelatinize to a jelly-like mass.

At approximately 480 F. a reaction develops within the oil causing it to expand very rapidly and give oif a dense vapor which is allowed to pass upwardly through the outlet 32 intothe trap 33 and reflux coil 35 where it is condensed to a liquid which is fed back into the kettle by gravity. Meanwhile the temperature in the kettle is being elevated until it reaches approximately 680 F. During this time interval at which the temperature of the oil is rising from 480 F. to 680 F. the liquid distillate is rapidly returning to the body of oil within the kettle. This condensed vapor or distillate appears to be necessary for preventing polymerization or other gelatinization of the china wood oil. At approximately 680 F. the valve 50 is opened to permit the escape of some of the distilled fraction, 8% by volume of the original charge of china wood oil having been found to be a desirable percentage for removal. If this percentage of distillate is not removed, the final oil body is practically non-drying. Where approximately 8% is removed, the oil is non-drying under normal conditions, but, however, may be dried to a tough, flexible film when heated to a temperature range between 300 F. and 350 F. A removal of 10% to 15% of the light fraction gives a semi-drying characteristic with.

to the final oil remaining in the kettle, and generally, the drying ability of the oil seems to increase linearly with the increase in percentage of removal of the light fraction. 680 F. seems to be the boiling point of the light fraction as the temperature remains stationary at this point until some of the light fraction is removed.

After the required percentage of distillate has been removed when the oil in the kettle is at approximately 680 F., the temperature is allowed to increase to about 700 F. after which the heat is cut off and the oil in the kettle allowed to cool to about 400 F. when it is removed through the valve 2|. The oil remaining in the kettle is a dark brown viscuous substance having several interesting properties. It is soluble in all the common solvents and mixes very readily with natural gums and resins, in fact more readily than when in its natural state as china wood oil. It has a speciflc gravity of 0.9812 at 32 C; when referred to water at 20 C. It is practically the same as water with which substance the oil is readily miscible and ordinarily inseparable, forming as it does, a type of emulsion. The substance is nearly odorless, a characteristic of great practical value, and has a viscosity at 200 F.'of 3030 seconds. The

. iodine number according to standard test procedure is 15.5. The oil promptly decolorizes potassium permanganate solution and iodine starch solution. I have found that when the oil is diluted with petroleum naphtha, it penetrates very rapidly into fabrics and even more thoroughly than does the untreated oil.

The distilled fraction is reddish brown or amber in color, has an offensive irritating odor, and shows an acid reaction. The distillate gives a positive test for formic acid but the amount present is small. Besides formic acid, there are other organic acids, the identities of which cannot be readily determined. The distillate decolorizes potassium permanganate solution and also iodine starch solution. The acidity is equivalent to 3.91 cc. of one-tenth normal alkali per cc. of the material, and the distillate has a pungent acid odor. The iodine number is 24.1 and the specific gravity is 0.8601 taken at 32 C. and referred to water at 20 C.

Both the light and heavy fractions of the raw china wood oil as is produced in the above manner, have interesting uses and applications other than already mentioned. The light fraction is a remarkable solvent for cellulose, as, for example, cellulose in wood which it removes leaving the woody fibre. It is also a solvent or plasticizer for rubber. It is also the only known solvent for gelatinized or polymerized china wood oil. It is miscible with water forming an emulsion there- It is highly penetrating within fabrics and woods. It is an eillcient solvent for paints and may be used as a paint remover, and it is a valuable solvent for all the natural resins.

The heavy fraction, in addition to the uses mentioned, acts also as a plasticizer 'for rubber; is readily miscible with water as an emulsion, being practically inseparable therefrom after mixture; and penetrates fabrics very readily. In'

addition, because of its high temperature, being usable with safety up to 850 F. or higher than any other known vegetable oil, it is particularly of value in use with friction fabrics, in insula-v tion coatings for magnetic wire,and other uses. Because of entire freedom from polymerization, it may be readily used in simplified processes for the manufacture of varnishes. lacquers, etc. It

may be readily combined with other oils including animal and mineral oils for lubrication purposes where its high penetrating characteristic imparts greater value to the oil as a lubricator. Generally as a bonding material usable in connection with the manufacture of linoleums and miscellaneous waterproofing materials, varnishes and enamels, brake lining, insulation, etc., and as a fiuxing material for natural gums and resins it has special utility.

In the description of the process for making the heat treated china wood oil, I have described and illustrated a special form of apparatus, the primary purpose of which is to permit the manufacture of the perfected oil without danger of fire. It is obvious, of course, thatother apparatus could be used; in fact the manufacture of the product is possible in open receptacles or kettles provided the capacity of the kettles are such that there would be no overflow of the treated oil. I do not advocate the use of open kettles, however, because of the constant danger of fire, and my improved apparatus completely overcomes the fire hazard.

As previously indicated, the raw substance is commercialchina wood oil. This is the oil of commerce available to purchasers in the United States, and while it has no clearly defined chemical characteristics, it meets certain purity standards established by trade associations. Japan wood oil in general does not have the same physical and chemical characteristics as china wood oil but the apparatus and process may be applied successfully thereto particularly in controlling the fire hazard and taking care of distillate reflux and liquid expansion.

Various modifications of the invention, as herein described, may be made, and, therefore, I do not desire to be limited to the disclosure except as required by the claims hereto appended: v

What I desire to secure by Letters Patent and claim is: a

1. A process of heat treating china wood oil which consists in subjecting crude commercial china wood oil at room temperatures to heat in quantities sufilcient to raise the temperature at 33 F. or more per minute with condensation of the vapors arising from the heated oil and return of said condensed vapors to the oil until a temperature of approximately 680 F. is reached, then permanently removing a portion of the volatile distillate of the oil, and thereafter raising the temperature to 700 F. after which the oil is permitted to cool.

2. A process of heat treating china wood oil which consists in heating crude china wood oil in a container to 680 F. at a minimum rate of 33 F. per minute, with condensation of the vapors arising from the heated oil and return of said condensed vapors to the oil removing between 1% and 30% of the oil by distillation at said temperature and permitting the oil to cool.

3. A process of heat treating crude china wood oil which consists in heating the oil in closed containers to a temperature of approximately 680 F. at a rate of approximately 40 F. per minute, condensing the vapor arising from said heated oil and returning the condensed vapor to the oil, permanently separating 8% of the distillate from the oil when its temperature is arlound 680 F., and finally cooling the heated or 4. A heat-treated china wood oil defined by a specific gravity of 0.98 at 32 C. referred to water at 20 C., a boiling point over 850 R, an iodine number of 15.5, and a viscosity at 200 F. of 3030 seconds, said oil forming an emulsion with water, being a plasticizer for rubber, having the property of not polymerizing when heated, being of a dark brown color and acting as a solvent for rubber, polymerized china wood oil and natural resins, said oil being prepared by heating china wood oil to a temperature of above 600 F. without gelatinization and with the removal of volatile constituents at said elevated temperature.

5. A heat treated china wood oil formed by heating from room temperature crude china wood oil to a temperature of 680 F. at a rate of 33 F. or more per minute, returning distilla tion products formed under 680 F. to the oil base, removing the distillate to an amount equal to 8% by volume of the oil base when its temperature reaches 680 F., and permitting the oil to cool.

6. A distillate of non-gelatinized china wood oil having a specific gravity of 0.86 taken at 32 C. and referred to water at 20 C., which has an iodine number of 24.1 and an acidity equivalent to 3.91 cc. of one-tenth normal alkali per cc. of the substance, which has a viscosity at 200 F. at 30 seconds and which is a solvent for rubber, polymerized china wood oil, paints and natural resins. and which is miscible with water to form an emulsion, said distillate being obtained from china wood oil which has been heated to over 600 F. without gelatinization and with condensation of the vapors arising from the heated oil and return of said condensed vapors to the oil.

'7. A process of heat treating china wood oil which consists in subjecting crude commercial china wood oil at room temperatures to heat in quantities sufiicient to raise the temperature at 30 F. or more per minute with condensation of the vapors arising from the heated oil and return of said condensed vapors to the oil until a temperature of above 600 F. and below 700 F. is reached, then permanently removing a portion of the volatile distillation of the oil, and thereafter raising the temperature to 700 F. after which the oil is permitted to cool.

8. A process of heat treating china wood oil which consists in heating crude china wood oil in a container to above 600 F. and below 700 F. at a minimum rate of 30 F. per minute with condensation of the vapors arising from theheated oil and return of said condensed vapors to the oil, removing between 1% and 30% of the oil by distillation at said temperature and permitting the oil to cool.

9. A process of heat treating crude china wood oil which consists in heating the oil in closed containers to a temperature of above 600 F. at a rate of approximately 40 F. per minute, first condensing the vapor arising from said heated oil and returning the condensed vapor to the oil, then permanently separating a minor fraction of the distillate from the oil when its temperature is above 600 F. and finally cooling the heated oil.

WILLIAM NANFELDT. 

